Method of and machine for conveying concrete



Dec. 19, 1933. BoNGARD-r 1,940,529

METHOD OF AND MACHINE FOR CONVEYING CONCRETE Filed July 18, 1931 2 Sheets-Sheet 1 illllllllllillllllllll HIIHIIHHII! llllmlllll HIHIIII 3nventor ERNST BONGARDT ((ttornegs. v

Dec. 19, 1933. E. BONGARDT METHOD OF AND MACHINE FOR CONVEYING CONCRETE Filed July 18, 1931 2 Sheets-Sheet 2 3nventor E RN ST BONGARDT 20 Fig. ma vertical Patented Dec. 19, 1933 QErnst .CONYEYING CONCRETE 7 Bongardt. Mainz-on-the-Rhinc, Germany Application July 18, 1931, Serial No. 551,727, and y y r in Germany May 20, 1927 p 9 Claims. f (on. 83-43) The invention relates to method of and means for mixing, lconveyingand distributing concrete, mortar and the like. l

Among the objects of i the invention are to pro- 5 vide an improved means and'method whereby thiswork can beeconomically and rapidly per formed using a large volume of'air at low pressure as the propelling agen 4 The invention is embodied in the example herein shown and described. r y p V In the accompanying drawings- Figure 1 is a side view' of the hopper and breaker. I ff H Fig.2 is an elevation looking at the left hand v sideof Fig. 1.

' Fig. 3 is a top plan view of what is shown in Fig.1. 1 Fig. 4 is a vertical section of thebreaker chamber-and a portionof; the sore section of the discharge end of the conveyor pipe} i Fig. 6 is a sectional detail on a largeinsc ale. of the water supply means." n M T Fig. 7 is 'a view looking into the right handend 125 of Fig. 6.

The apparatus for carrying out the invention includes the following: A hopper 1 0 into which the materials of the concreteare first supplied in a lightly .moistened condition. In the chamber 11 'of the hopper is ascrew 12 on a driven shaft 12 for feeding thematerials] The screw is somewhat spaced from the bottom of the hopperso as to allow an accumulation of cement andgsanda'nd thereby facilitate theaction of the screw in feeding large gravel or pieces of stone into the chamber 13 now to be referredto.

The chamber 11 opens into another chamber. 13-

into which'the materials are fedysaid chamber 13 having parallel vertical sides andto these sides are pivoted upper and lower compressor plates 15 and 16 each acted on by a roller on the ends of crank arms -17 and 18 on shafts-19' and 20 to press them toward each other; The lower one of thepressure plates has a downward- .ly bent. flange to guide the material-into the blowing line. The means for imparting the pressure to said rollers and plates consists of a pair of levers 21 and 22 fulcrumed on the external ends of ;a shaft 23,- said levers each connected by, links, 24 and 25 with crank arms 26 and 2'7 carrying the internal roller-bearing crank arms 19 and 20. Each flever'21 and 2 2 has on itsfree end an adjustable weight 28 that can beadjusted and fixed thereon so that the pressure to ,be applied to the plates l5 land 16 can 'be variedfltocompact can be slid around the rim 33 this chamber and itsopening drivingpressure on the materials prior to' its to the desired-degree the mass beingfed-into the chamber 13. The effect of the compressing plates is to form a tight plug of the materials and to substantially prevent the drivingblast of air from V backing into the screw chamber. A by-pass 40 is provided to balance the pressure in the chamber 13 with the main pipe line. 'Otherwise said chamber is madeas tight as practicable, closures at the top and bottom being provided to afford access for cleaning. r p 7 7 Fixed on the shaft 12 is a bladedbreaker member 14 that cuts the compressed concrete mixture into small portions after it projects into thechamber 13.

30 designates the blower, the air discharge of '19,

which is connected with a pipe line 31'for con ducting the concretematerials to the pointwherc itis to be deposited, The pipe line 31 can be constructed of any suitable numberof sections according tothe workto be done, the last or dis: 75, charging section being flexible so that it canbe moved about to distribute the 'material discharged. 1 p

. The chamber 13 discharges into the pipe line by vmeans ofya connecting conductor 13%;. and just 811 below the point ofintersection ofthe two is a hinged closure 31 that can be opened to inspect and clear the interior of the pipe at'and adjacent the junction of the a o o i g. i l The airline from the. conductor :13 is located pipe andqconductor 13 in at a level somewhat below the level" of the pipe from the pump to said conductor 13 and a defiector isshown at ll-for diverting'and contracting the air current in the pipeline across thelower ,90 end of the connec ing conductor 13 and into the line beyond the intersection of the conductor.

The current of "air and the concretematerials are thus moving in the same general direction.

I The 'end of-the pipe line 31is equipped with an expanded chamber 32 composedof two conical portions connected at their basesby a narrow rim 7 33 provided with slots or openings34; and a movabie ring 35'isalso provided with openings that to partially or .The function of is to. release the completely open said slots 34.-

final discharge as it is undesirable that the material should be discharged with great violence at'the point of deposit. Beyond .the said air or Y pressure release the momentumfof the material is largely relied on to carry it to such point of V discharge.

. 36designates theno z zle section of the air line,

said section being preferably flexible to facilitate distribution of the materials. A flexible water supply pipe'3'7 provided with a regulating valve 37 and a flared spray nozzle 38 is inserted between the flexible section and the air release, said water supply being extended inclinedly into the pipe line todischarge near the axis of thepipe and in'the direction of movement of the concrete materials. Said nozzle is protected from the wearing action of the moving materials by means of an inclined shield 39.

The apparatus can be used for depositing concrete materials in either high or'low places, as for example, in paving a street or making the floors in buildings. I

In practice and in carrying out the method in-- volved herein the concrete material is fed .into

' the chamber in a quantity having a cross section equal to from one sixth to one tenth the cross section of the main pipe line. The concrete materials including thecement, gravel etc. are introducedinto the apparatus fairly dry. For example, cnlyabout four gallons of water to one bag of'cement'or a hundred pounds of cement is used, or 'so that the water cannot evaporate and permit the material to settle onto the pipe line. If there be too much water some of the material is likely to settle on the bottom of the pipeline.

The pressure to be generated by the air blower is p'referably'from five to ten pounds according to the length of pipe and the height to which the "material isto be carried. The volume of air should be about one hundred times the volume of the material, hence the material is moved rapidly with a large volume of air but at comparatively low pressure. Owing to its friction on the walls of the pipe the air travels fastest along the axis of the pipe thereby-tending to entrain the material along said axis. The slower traveling air I hugs the walls of the pipe and forms a bolster preventing the walls of the pipe fromwearingo'ut rapidly. 1 a

The quantity of water introduced at the'd-ischarge end of the pipe line-is determined by the slump desired in the deposited'materials, such slump varying according to the required type of work to be done, The materials are those ordinarilyused but varied according to specifications particularly required, r

The forms of the parts of the apparatus can be changed without "departing'from-the gist of the inventionas-claimed, 1 5

-What I claim is:; i j

1. 111 apparatus-for pneumaticallymixing and conveying concrete materials, a hopper for said materials, a material feeding means in said hopper, a chamber withwhich said hopper communicates and into which the material is'fed by the feeding means, and a pressure operated yielding means in said chamber beyond said feeding means for compressing the fed materials to forma plug of the material between the hopper and said chamber. 7

2. In apparatus for pneumaticallymixing and conveying concrete materials, a hopper for said materials, a concrete feeding means in said hopper, 'a chamber with which said hopper communicates and into which the material is fed by the feeding means,'a pressure operated yielding means in said chamber beyond said feeding means for compressing the fed concrete toform a plug between the hopper and said chamber, and bladed means in said chamber actuated-by the feeding means for breaking'said plug-into portionswithin saidch'amber.

3. In apparatus for pneumatically mixing and conveying concrete materials, a blower and a pipe line, a hopper for the materials, a material feeding means in said hopper, a chamber with which said hopper communicates and into which the material is fed by the feeding means, said chamber discharging into the pipe line, a yielding 'pressure operated means in said chamber beyond said feeding means for compressing the fed concrete to form a plug between the hopper and said chamber, and a pressure balancing bypass pipe ;connecting the pipe line and said chamber at a point between the blower and the concrete discharge from said chamber.

4."In apparatus for pneumatically mixing and conveying concrete materials, a blower and a pipe line, a hopper for the concrete materials, a material feeding means in said hopper, a chamber' into which said hopper communicates and into whichvthe material is fed by the feeding means, a pressure operated resilient means for compressing the fed concrete'to form a plug in said chamber beyond said feeding means, said chamber discharging the material by gravity into the pipe line, and a deflector in said pipe line directing the blast of the blower into the materialsin substantially the direction of their movement into the line.

5. In apparatus for pneumatically mixing and conveying concrete materials, a blower and a pipe line, a hopper for th'e'concrete material, a material feeding means in said hopper, a chamber with which said hopper communicates and into which themateria'l' is fed by the feeding means, a pressure operated yielding means forcompressing the fed concrete to form a plug-between the hopper and said chamber, said chamber discharging'the material by gravity into the pipe line and a deflector in said pipe line directing and condensing the blast of the blower into the materials in substantially the direction of their movementintothe line;

III)

6. In apparatus for pneumatically mixing and conveying concrete materials; a hopper for the material, a material feeding means in said hopper, a chamber with which said hopper communicates and into which the material is fed by the feeding means, 'a conveying pipe line connected with said chamber, yielding means for compressing the fed material to form a plug between the hopper and said chamber, said pipe line having a discharge member spaced from the pipe line and a pipe line pressure relief consisting of an enlarged chamber connecting the terminus of the" pipeline and said discharge member and surrounding the discharge terminus of the pipe line, said 'enlarged chamber provided with a perforated rim laterally remote from said terminus of the pipe line.

'7. In apparatus for. pneumatically mixing and conveying concrete materials, a hopper for the material, a material feeding means in said hopper, a chamber with which said hopper communicates and into which the material is fed by the and said discharge member and surroundingthe discharge terminus of the pipe line, said enlarged chamberprovide'd with a perforated rim laterally are remote from said terminus of the pipe line and an adjustable closure for said perforated rim.

8. In apparatus for pneumatically mixing and conveying concrete materials, a hopper for said materials, a material feeding means in said hopper, a chamber with which saidhopper communicates and into which the material is fed by said feeding means, a pressure operated yielding means in said chamber beyond said feeding means for compressing the fed materials to form a plug of the material between the hopper and said chamber, and means whereby the pressure of said plug forming means may be varied.

form a plug of the material in said chamber and a bladed member actuated with said feeding screw beyond said plug forming means tojbreak up said plug into chunks.

ERNST BONGARD' I. 

